1. Field of the Invention
The present invention relates to a measurement bearing, in particular for a wheel set of a rail vehicle, having a rotational axis and at least one first bearing ring. The first bearing ring defines a main supporting direction and a circumferential direction extending transversally with respect to the main supporting direction. The first bearing ring is also designed to take up bearing forces which have at least one force component in the main supporting direction and, during operation, said bearing forces are applied to the first bearing ring via a plurality of rolling bodies. The present invention also relates to a bogie for a rail vehicle with such a measurement bearing. Finally, the invention relates to a method for determining the mechanical loads on a measurement bearing.
2. Description of the Related Art
Roller bearings are used in a large number of different forms to transfer radial and/or axial loads between components rotating in relation to one another. Here, the components of the roller bearing may be subject to various load cases (e.g. static and/or dynamic load, rotating and/or stationary load, etc.) according to the application, for which the bearing must be designed accordingly. It is indeed possible to extensively model the bearing and the expected load cases and to use simulation calculations for the design of such a bearing. The problem remains, however, that for the expected load cases a certain simplification must necessarily be applied. Difficulties also arise in taking account of production and assembly tolerances in such model calculations.
It is also known for the actual load cases affecting a bearing during operation to be estimated by analysis of the contact pattern or the deterioration pattern of a worn bearing. Here again, however, it is difficult to draw any conclusions about the actual load situation during operation.
The abovementioned models of the roller bearing are also used, inter alia, in methods for identification of the (deterioration) state of a roller bearing of this type. For example, such a method is known from EP 1 197 415 B1. Here, dynamic measurements (via acceleration sensors) in the area of a bearing are used to draw conclusions about its level of deterioration by means of modelling the bearing.
Through a later analysis of the measured bearing a further refinement of the model can indeed take place. But the problem remains that only secondary information on the actual loads on the bearing can be obtained.
Wheel set bearings of rail vehicles are as a rule subject to comparatively high loads, whilst at the same time for such wheel set bearings a long service life is demanded. This applies in particular to the wheel set bearings of high speed vehicles. Despite comparatively great efforts in the design of wheel set bearings and high quality of manufacture, from time to time damage is observed, the causes of which are unclear.